As a volunteer at Little Bit Therapeutic Riding Center, I groom and saddle up a horse on Friday mornings before trekking along in a parade of rider, therapist, leader and sidewalker (me). The first week, the assigned horse was Spencer, who scooted over to rest his butt against the stall door when I tied him up to be brushed. The person with me said something about his being difficult today. Translating from dogspeak, I guessed what Spencer wanted. I grabbed the curry comb and gave him a good scrub at the point where tail meets butt, just as you'd do with a dog. Problem solved. He stood nicely for the rest of the grooming session.
Dogs and horses generally speak the same language but I guess tail-ends often do.